AST - Passivation Stainless Steel Parts - Brochure

Passivation is a chemical treatment applied to stainless steel parts to provide resistance to oxidation, rusting and mild chemical attack. The Passivation process removes free iron (ferric material) from the surface of the parts that can be created during finishing operations such as milling, buffing, lapping, cutting, etc. These contaminants create potential sites for corrosion that result in premature deterioration of the component. The acids used for Passivation dissolve much of the alloyed iron on an atomic level right at the surface leaving a chromium and nickel-rich surface. It then creates the formation of a thin oxide film that protects the stainless steel from corrosion.